Drill



Dec. 24, 1935. G, G, BROWN 1' 2,025,5 7

DRILL Filed Oct. 6, 1951 INVENTOR 1/ t/amnamg law/z ATTORNEYS PatentedDec. 24, 1935 UNITED STATES PATENT OFFICE Application October 6,

10 Claims.

This invention relates to drills, and more particularly to rock drillscomprising a sleeve carried by the bit within the open upper end ofwhich a drill shank is inserted and secured by a keeper.

In such constructions, the forces operating to separate the drill partsare applied directly on the keeper in shear, resulting in rapid wear,gradual loosening of and play between the parts, and short life of thedrill.

The main object of the present invention is to provide a drillconstruction in which these forces are borne directly by the moresubstantial drill parts and no force in shear is applied on the keeper,which merely operates to hold the drill parts in proper engagement forsustaining these forces.

With this object in View, the invention consists in certain features,combinations, details of construction and arrangements of parts whichwill first be described in connection with the accompanying drawingshowing the invention in preferred forms and then more particularlypointed out in the claims.

In the drawing:

Figure 1 is an exploded perspective view of a drill embodying one formof the invention;

Figure 2 is a top plan view of this drill with the drill shank insection;

Figure 3 is a section taken on line 3--3 of Figure 2;

Figure 4 is a view similar to Figure 2 showing a modification; and

Figure 5 is a section on line 55 of Figure 4.

Referring to the drawing, the drill shown by way of illustrationcomprises, .generally, a drill bit I0 having on its lower face drillingteeth II and on its upper face an open ended sleeve I2, within which isinserted the lower end of a drill shank I3. For convenience ofmanufacture, the sleeve I2 is shown as a separate piece which will bewelded onto the drill bit Ill, but may be formed integral therewith. Thesleeve I2 is of angular form to substantially correspond to the angulardrill shank I3 to provide a non-rotary connection between these parts,these parts being shown as of the preferred hexagonal form.

In accordance with the present invention, the drill bit sleeve and drillshank are so modified in shape as to provide cooperating engagingsurfaces adapted to receive directly and sustain the separational forcesof the drill, and means is provided for holding and maintaining thecooperating engaging surfaces of the drill bit sleeve and drill shank inrigid connection,

1931, Serial No. 567,162

For this purpose, the sleeve I2 is formed with all its sides normal tothe bit IIJ, excepting only the inner side wall I, which is inclinedinwardly and upwardly from the bottom to the top of the sleeve I2, and,because of this inclination of 5. side wall I, the sleeve I2 is madesubstantially larger than the shank I3. The lower end of drill shank I3is provided with a similar, but oppositely inclined side for cooperativeengagement with the inclined side wall I, by forming an undercut 2 andremoving the metal from the inner end of undercut 2 to the lower edge ofthis side of the shank I3 to provide a downwardly enlarging taper 3. Topermit assembly of the shank IE5 within sleeve I2 with taper 3 andinclined side Wall I in proper engagement, the opposite corners a and bof sleeve I2 are preferably squared slightly as shown. It will beunderstood that the shank is off center to the bit as introduced intothe sleeve, but brought into central position when the walls I and 3 arein locked position.

Holding means is also provided for maintaining the cooperating engagingsurfaces I and 3 of, respectively, sleeve I2 and shank I3 in tightinterlocking engagement. As shown in Figures 1-3, this holding meanscomprises a suitable filler sleeve 4, a keeper 5 and a keyway or slot 6formed partially in filler sleeve 4 and partially in the sleeve I2, theslot 6 being, preferably, slightly smaller than the keeper 5 to securesufficient Wedging action to force the interlocking faces of sleeve I2and shank I3 into tight engagement. After the coupling has been made,the ends of keeper 5 may be upset against the exterior of sleeve l2, asshown at I. The holding means may be of any other form suitable to holdthe parts in proper position.

In assembling the drill parts, the end of drill shank I3 is inserted inthe sleeve I2 with the interlocking walls 3 and I opposite each otherand the shank moved sidewise to engage these walls. The filler sleeve 4is then placed within sleeve I2 and keeper 5 forced through slot 6 tobind the parts tightly together and its ends are upset as shown at I. Inorder to separate the parts for removal of the bit or repairs, it isonly necessary to reverse the above steps.

In the modification shown in Figures 4 and 5,

' the holding means comprises solely the slots 8, 8' formed in oppositesides of the sleeve I2, as shown, and the keeper 9, which in this caseis of sufficient size to tightly fit between shank I3 and the inner wallof sleeve I2, and the keeper being of sufficient width to hold the partsfirmly together.

It will be understood that the invention is applicable to types ofdrills other than that shown and that the invention is not to be limitedto the constructional details shown and described as these may be variedwithin the invention as defined by the claims.

What I claim is:

l. A drill comprising a bit, an open ended sleeve carried by the bit andhaving a continuous side wall, a drill shank inserted within saidsleeve, a non-rotary connection between the sleeve and shank,interlocking inclined surfaces on said sleeve and shank preventingwithdrawal of the shank from the sleeve, and holding means comprising afiller member between the shank and sleeve, and a keeper and slot forholding said shank and sleeve in such interlocking and nonrotatingengagement.

2. A drill comprising a bit, an angular open endedsleeve carried by saidbit and having a continuous side wall with an inwardly upwardly inclinedportion, an angular drill shank inserted within .said sleeve and havingon one side a downward outward tapercooperating with the inclinedportion of the side wall of said sleeve to secure an interlockingengagement therewith, and holding means for maintaining the interlockinginclined surfaces of said sleeve and shank in tight engagement.

3. A drill comprising a bit, an angular open ended sleeve carried bysaid bit and having a continu'ous side wall with an inwardly upwardlyinclined portion, a drill shank inserted within said sleeve and havingon one side a downward outward taper cooperating with the inclined sidewall of said sleeve to secure an interlocking engagement therewith, andholding means comprising a keeper passing through the sleeve andmaintaining the interlocking inclined surfaces of said sleeve and shankin tight engagement.

4. A drill comprising a bit, an angular open ended sleeve carried bysaid bit and having an inwardly upwardly inclined side wall, an angulardrill shank inserted within said sleeve and having on one side adownward outward taper cooperating with the inclined side wall of saidsleeve to secure an interlocking engagement therewith, and a fillermember, said sleeve and filler having coacting slots, and a keeper insaid slots maintaining said sleeve and shank in tight engagement.

5. .A drill having on the bit an angular sleeve with inclined wall I,and opposite parallel surfaces a, b, angular shank l3 having inclinedside 3,'filler 4 between the sleeve and shank, said filler and sleevebeing slotted to form keyway 6, and a keeper 5 in said keyway andpassing through the sleeve walls for holding the shank and sleeve inposition.

6. A drill comprising a bit, a drill shank, an

open ended sleeve connection betwen the bit and shank, said sleevehaving a continuous side wall, inclined surfaces on the sleeve and shankcoacting to prevent withdrawal of the shank from the sleeve, and holdingmeans between the shank 5 and sleeve for maintaining the inclinedsurfaces in interlocking engagement.

'7. A drill comprising a bit, a drill shank, a sleeve connection betweenthe bit and shank, said sleeve having a continuous side wall and an open1 end, the open end of'said sleeve being formed to permit the passage ofthe shank oiT-center to the bit and to be centered by relative sidewisemovement of the shank and bit, and a keeper center the shank and sleeve,two of said members being formed to provide oppositely inclined surfacescoacting to lock the shank and bit together in centered position.

8. A drill comprising a bit, a drill shank, a sleeve connection betweenthe bit and shank, said sleeve having a continuous side wall and an openend, the open end of said sleeve being formed to permit the passage ofthe shank off-center to the bit and to be centered by relative sidewisemovement of the shank and bit, and a keeper between the sides of theshank and sleeve actingto center the shank and sleeve, a portion of thesleeve being formed as an inwardly upwardly inclined'wall, a portion ofthe shank being formed as an outwardly downwardly inclined surfacefacingthe inclined wall of the sleeve, said inclined surfaces coactingto lock the sleeve and shank together in centered position.

9. A drill comprising a bit, a drill shank, an angular sleeve connectionbetween the bit and shank, said angular sleeve having a. continuous sidewall and an open end, the open end of said sleeve being formed to permitthe passage of the shank off-center to the bit and to be centered byrelative sidewise movement of the shank and bit, and a keeper betweenthe sides of the shank and sleeve acting to center the shank and sleeve,two of said members being formed to provide 'opshank and bit together incentered position.

10. A drill having on the bit a sleeve "with vertically inclined wall I,Opposite parallel. surfaces a, 1), extending horizontally in a planenormal to between the sides of the shank and sleeve acting to 15positely inclined surfaces coacting to lock the the wall I, and planesurfaces on the sleeve extending at anangle to and between eachpedge ofthe inclined wall and one of the'surfaces a, b, angular shank l3 havingan inclined surface 3 and surfaces parallel with and coacting with theabove-mentioned plane surface 0 on the sleeve,

and a keeper holding said inclined surfaces and said coacting parallelsurfaces on the shank and sleeve together when moved into interlockingengagement by relative movement of the. sleeve and shank along saidsurfaces a, b.

' GOUVERNEUR G. BROWN.

